ABSTRACT
It is all too easy to demonstrate that people brought up in poor environments tend to achieve poorly in school and to score below average on intelligence tests, but practically impossible to disentangle the precise effects of any one factor. More often than not there is a syndrome of mutually interacting adverse factors, for example poverty, poor nutrition and health, overcrowded home, lack of intellectual stimulation, inferior language background, lack of parental interest in education, poor schooling, and insecure economic future all cooperating. In addition we have seen that the possibility of genetic differences cannot be neglected. We cannot, as with rats, study the effects of a single factor while holding other relevant conditions constant. Sometimes indeed the opportunity does occur to observe and measure the consequences of some fairly clearcut change, such as rehousing of slum families in a new area, or a change in methods of school teaching. But even here the results are equivocal — are they due to better health and less overcrowding, or to the development of greater self-respect and ambition among the rehoused families? Is there at the same time greater social discord or delinquency because the families have lost their familiar roots? How far does the ‘Hawthorne effect’ operate, i.e. do the experimental groups tend to show improved attitudes or achievements largely because they know they are being studied and this helps to motivate them, usually to produce the results the investigator wanted? And is any rise in achievement consequent on changes in teaching due more to the personalities and keenness of the teachers concerned than to the methods as such? Thus the classical experimental approach does not often provide the most convincing answers in the social sciences as it normally does in the biological.
